The Ultimate Philly Weather Forecast

Think the weather we’ve seen in the last couple of years has been crazy? In the next few decades, Philadelphia could transform from a Northern city into what feels like a Southern one. And that could change everything about who we are.

Obviously, I can’t predict precisely what will be going on outside your window as you’re reading this, but if it’s somehow, well, weird—90 degrees on Valentine’s Day, for example, or two feet of snow outside your Shore house, or, I don’t know, something that could never happen in Philadelphia … how about an earthquake?—that would be pretty consistent with what we’ve seen around here lately. Weatherwise, the last couple of years in Philadelphia have felt like something John Bolaris and Hurricane Schwartz came up with while tripping on LSD:

Snow! Two years ago was, I’m sure you’ll remember, the snowiest in the long history of the city, with Snowmageddon socking us with 78.7 inches of white stuff. (Last year, no slouch, clocked in with 44 inches, more than twice what’s normal.)

Heat! July of last year was the warmest on record, with the temperature hitting 90 degrees and above 21 times.

Rain! Thank you, Irene and Lee. The tropical-storm twins made last August and September the wettest two-month period in the region’s history, and for the year, we set another record with more than 64 inches of precipitation.

Storms! Speaking of Irene and Lee, 2011 also had the third-highest number of named storms in the Atlantic, reaching all the way to the letter “S” (the deceptively friendly-sounding Sean).

All in all, we’ve seen so much weather weirdness that our weather-obsessed city—which generally holds its meteorologists more accountable than its politicians—is asking one question: Is this just a freak blip on the Doppler? Or is it the start of something really big and scary and heinous: Permanent Climate Change?

In truth, nobody can tell you. One of the things you discover when you begin poking your nose into climate science is that few researchers are certain of anything. “We’re not sure, based on what climate scientists know, whether or not the storms we’ve seen recently are due to climate change,” says Gajewski. “But what we do know is that they look a lot like what we think storms would look like in a climate-change scenario.”

And there’s a pretty sizable—and growing—body of evidence that suggests something is going on when it comes to our climate. According to one report, over the past several decades the average winter temperature in Philadelphia has spiked by four degrees. No wonder the National Weather Service recently increased what it considers “normal” temps for our area. There’s also been an increase in both the number and the severity of storms along the Atlantic Coast. And the rate of sea-level rise there is the fastest in 2,000 years.

All of which raises the question: If this really is the beginning of climate change, how much change are we actually in for—not just in terms of polar bears and polar ice caps, but specifically here in Philly? Not surprisingly, there’s no consensus about this, either, even among the many scientists who believe that global warming is real and being exacerbated by humans. But there are some eye-popping prognostications. The most provocative come from the Union of Concerned Scientists, a group of environmental researchers who predict the following for Pennsylvania and New Jersey if greenhouse gas emissions continue to rise:

While snow will become pretty rare, there will be a rise in both the amount and the intensity of precipitation.

The level of the Atlantic­ Ocean will continue to climb, potentially by more than three feet.

The climate in Southeastern Pennsylvania will only continue to heat up, and by the end of the century the weather here could be similar to what we see right now in southern Georgia—with more than 80 days per year topping 90 degrees and 25 topping 100 degrees.

Even if those predictions turn out to be only partially true, the effect on the lives of Philadelphians could be pretty large. Indeed, cities around the world now potentially find themselves at the beginning of what amounts to a grand social experiment: What happens when you radically change the weather that’s long defined you? Will foggy old London still be charming and proper if it’s 90 degrees and sunny much of the time? Will Minnesotans be so hale and hardy if the temperature there barely drops below freezing anymore?

And will Philadelphia—not to mention Philadelphians—still be the same if our climate looks like the love child of Atlanta, Seattle and natural-disaster-magnet Haiti?

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